IR Lap Timing Project for FPV Quadcopter racing

I made some progress on the Quad Copter lap Timing system this past week.  I have completed the Transmitter portion, see the pics below. What you are seeing is a long Start bit followed by 0b0010000 plus parity. Modulation is at 57.6 Khz

 I have started working on the Receiver and I think I have the base code to receive the ID from the Xmtr. But now there are a lot of architecture options on how to proceed forward and I would like some PaxSpace input. I will be there tomorrow night for Micro-Controller Monday and show what I have done so far and we can discuss the way forward.
My initial architecture is as follows:
  1. There will be 4 or more receivers talking to a base station
    1. A 5 wire ribbon cable is used to connect the Base Station to the Rcvr
      1. +5v, Gnd, SDA, SDC, Time Sync
  2. Base station is either:
    1. Arduino talking to a laptop via USB/WiFi
    2. Raspberry Pi to a laptop via USB/WiFi
  3. I2C is used to talk to the Base Station from the Rcvr
    1. The Base Station is the slave and the Rcvr are the Masters
    2. Each time the Receiver registers a Xmtr reception it transmit or I2C to the Master
    3. Each Xmtr sends the ID and the time of the event
  4. Time synchronization Options:
    1. A time sync pulse is sent once a minute or less to sync the Rcvrs. A internal timer counts milliseconds between sync pulses
    2. The sync pulse is sent at 1 Khz and a way is figured out to embed a reset pulse.
    3. An IRIG like time stamp is sent over the 1 Khz pulse train
I need some help creating the circuit boards for this project. I have done it in the past, but I think my methods are a little out dated.


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Cutting Acrylic on PaxSpace’s CNC Router

CNC Box AfterCut

Using the CNC Router to make the electronics box for the CNC Router.

Design was done in Sketchup 2014 with interlocking tabs.

I used the SketchUCam plugin from Phlatscriptboyz to ready the design for the CNC Router. The SketchUCam plugin has two tool bars that work together. One is called PhlatBones that helps solves a common CNC problem. As you can see in my design I have square corners on all of my tabs for interlocking the box together. It is hard to cut a square corner with a round bit. SketchUCam PhlatBones script tools makes it easy to create the rounded corners so that all the pieces fit together nicely. It creates a small gap at each corner. If this is not acceptable then the corners may need to be cut out manually with a band saw.

The second tool bar is used for assigning all the cuts to the drawing. First thing is to configure SketchUCam to know what kind of bit I was using. In this case it was a 1/4″ bit, plus the speeds I wanted to use while cutting. I then started using the tools to assign cuts to my drawing. I used the “Insided Cut” tool for the circles. “Outside Cut” tool for the outside frame, and the “Centerline Cut” tool for the fan grill lines.  The Sketchup “group” command can then be used to group certain cuts together based on user preference. The “Tab” tool was then used to add tabs to the outside lines so that the piece being worked did not move while being cut. The settings for the tabs was 3/8″ wide with 50% cut-through. You can see some of the tabs in the picture above. These were easy to snap off after cutting.

Next step was to generate the G-Code using the “Generate G-Code” green arrow tool. This runs the script to generate the G-Code and then displays the cuts visually with a built in viewer. This is inspected to see if G-Code is doing what the user intended.

I copied the G-Code cnc file over to the CNC Router and after setting the zero point of the router, started the router cutting. I used the shop vac to vacuum the acrylic bits and to hold the material down.  Two more projects for the CNC router is a vacuum shoe and a vacuum table.

I snapped the pieces out of the big acrylic sheet and sanded the tabs flush with the edges.  I temporarily taped the box together to see what it looked like and how well if fit together. I have a few holes that I have to drill before I put it together. I still need to work out how to change bits in the middle of the cut.

Part of building the CNC electronics box is to add 3 new control buttons and the Emergency Stop switch that should make operating the CNC router easier. I plan to have a class on the CNC router at that time that should be in the near future.


CNC Box Taped

CNC Router is working!!!!

cnc smile

This is the first real object that has been cut by our CNC Router!

The PaxSpace CNC Router works, but it is not ready for member use yet. The following tasks need to completed:

  • The electrical box layout and wiring still needs to be designed and finished.  Most of the parts are in hand.
  • The control computer/keyboard stand needs to be designed and built.
    Shout-out and Bravo Zulu to Matt Virts for getting the touch screen working.
  • More permanent legs still need to be designed and built.
    Something simple about 32″ high using 2x4s with cross bracing
  • The MDF spoilboard needs to be cut to size and mounted.
  • A work mounting and clamping system needs to be designed and built.

Most Important:  There are many possible work-flows for using the CNC router.  We need to figure out what combination of tools and programs we want to use to later teach to our membership. This is fairly new to just about everybody in the space.

I would like to get more members participation in these final steps. Please come out and support the final build-up.

Lets plan a CNC Router meeting and demo for Thursday at 6PM from 7:30 to 9PM.  Use the CNC Router forum for any questions or comments.

Cool KickStarter, Chip Sized Arduino with OLED Display

MicroView Arduino

I recently found this cool KickStarter, It is an chip sized Arduino with a built-in OLED display.
The “microview” will be manufactured by SparkFun right here in the USA!!!

It is only $45 by itself or $55 with the USB Programmer.
Compare that to just an Arduino UNO at ~$28. Quite the deal!
Just 13 days left to go with delivery expected August 2014.

Check it out!



  • Support for the Arduino™ IDE 1.0+ (OSX/Win/Linux)
  • 100% Arduino™ Compatible
  • Built-in 64×48 OLED display
  • Direct 3.3VDC – 16VDC power input, no power regulator needed
  • Standard DIP Package
  • Breadboard friendly or direct solder


  • Display: 64×48 OLED Display
  • Microcontroller: ATmega328P
  • Operating Voltage: 5V
  • Input Voltage: 3.3VDC – 16VDC
  • Digital I/O Pins: 12 (of which 3 provide PWM output)
  • Analog Input Pins: 6
  • Flash Memory: 32 KB
  • SRAM: 2 KB
  • EEPROM: 1 Kilobyte
  • Clock Speed: 16 Mhz
  • No other components required


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CNC Router CDR Design is Ready!!!

Router 102 Profile


We had our “PDR” Design review last Friday and have made a few changes and added the X Axis bed to the Gantry design.

The CNC Router CDR Design review is scheduled for 7:00 PM on Tuesday the 25th of February.

We want the CNC Router completed and up and running by Open House that is March 23rd.

This will hopefully be the final design review for the first iteration of PaxSpace’s CNC Router.

After the design review, Parts will be ordered and a build party will be scheduled.

If you do not come to the CDR, Do not complain your voice was not heard.

CDR Design material can be found on the wiki page.

CNC Router CDR Event Link

CNC Router Wiki Link

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Intro to Arduino Part 1 of 2

This is the intro to the Arduino microcontroller  and electronics in general.  No electronics experience is required.

Part 1, will be 1 1/2 hours long from 7:00 to 8:30 PM, with time afterword for open experimentation.

Date: Monday, February 24th, 2014

The class will start with basic electronics and then programming the Arduino microcontroller.

There is room for 10 students working in pairs.

Please register. If the class is fully registered, Only registered members may attend. If there are slots open, the remaining student slots will be filled on a first come, first serve basis.

Event Link: 
Intro to Arduino Part 1 of 2



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Message from a Sponsor: Linking innovative technology with University System of MD resources presentation

The Patuxent Partnership (one of our sponsors) is holding a briefing that is open to the public. We wanted to share this opportunity with our viewers and membership. If you have a moment, be sure to look through what they have to offer!

The Patuxent Partnership
invites our Members and the regional community to a briefing on
Linking innovative technology with University System of MD resources:
Maryland Technology Enterprise Institute’s (Mtech) Maryland Industrial Partnerships (MIPS) & I-Corps
Mr. Joe Naft, Director, Maryland Industrial Partnerships (MIPS)

Thursday, February 6, 2014

 11:00am Check-in; 11:15am Program; 12:30pm Conclude

Wyle Building 1 North, Conference Room, Exploration Drive, Lexington Park, MD  

This is a no cost program. 

Seating is limited. Advance registration is required to guarantee your seat.  Doors open at 11:00am.
To Register, Click HERE 

One of Mtech’s missions is to:
 Maryland companies with university resources to help them succeed through the MIPS program.

Maryland Industrial Partnerships (MIPS)- for more information click HERE

Maryland Industrial Partnerships (MIPS) promotes the development and commercialization of products and processes through industry/university research partnerships.  MIPS provides matching funds to help Maryland companies pay for the university research.  Projects are initiated by the companies to meet their own research and development goals.

Through MIPS, Maryland firms have the opportunity to leverage their research and development funds and gain access to the creative talents and extensive research base of the University System of Maryland.  MIPS matching funds are awarded on a competitive basis for projects based on proposals submitted jointly by Maryland companies and researchers from any of the 13 University System institutions.


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3D Printing Class tomorrow on Friday, January 24th at 6PM

Plate Stand

Last minute 3D Printer class is now scheduled for tomorrow night on January 24th, 2014 from 6PM – 8PM

Please signup on the PaxSpace calendar when it shows up, Should be soon. Or click the Menu Item “Events”  (Not Calendar or My Bookings)

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PaxSpace CNC Router is moving forward

To get this project started, We have decided to purchase the core set of electronics to begin the CNC Router project.

The goal is to build a 2’x4′ CNC Router at low cost with the capability for future upgrades.

After canvasing the internet, We have developed the following Bill of Material (BOM) for the electronics.  If you would like to proposed alternative parts, please reply in the Project : CNC Router: CNC Electronics Forums with your proposal that we may not have thought of yet.

Plan to purchase Friday 1/17/2014 unless someone has any objections. This project is being funded through donations made to the CNC Router project.

1) We have decided to go with an Arduino based controller, with GRBL Firmare: An open source, embedded, high performance g-code-parser and CNC milling controller written in optimized C that will run on a straight Arduino. WebLink:

2)#23-205-DS8 285oz-in bipolar rating, 205oz-in unipolar rating. 3v, 3A, 200 S/R, 2.2mH, Size #23, Dual Shaft (HobbyCNC, $46 x 3) :NEMA 23 Bipolar Motors for maximum torque with a good price per performance that matches our chosen drivers. WebLink:

3) SainSmart CNC Router Single 1 Axis 3.5A TB6560 Driver (SainSmart, $13.99 x 3):  High Current, Good Features, Good Quality that should last the life of our router. WebLink:

4) 24V 15A 360W DC Regulated Switching Power Supply (Amazon, $27.98) Cheap good power supply that can be adjusted up to approximately 29.5V: WebLink:

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President’s Update

First of all, I would like to wish everyone a safe and Happy Thanksgiving. For those that are staying local over the long Thanksgiving weekend, I hope you will use the time to work on some of your projects at PaxSpace and show off your Makerspace to your friends and relatives.

PaxSpace had a great turnout at the Open House on November 3rd, It was also our official kickoff for PaxSpace to be an operational Makerspace. We had more than 50 people on the sign in sheet and estimate over 100 people visited the space on that day.

Our Quartermaster Paul Di Biase has been providing the required safety training for our members. Please attend a safety training class if you haven’t already. See the calendar for upcoming classes or contact Paul at to arrange training.

Thank you to all members that helped SMARTCO move to their new location. PaxSpace is looking forward to working with SMARTCO in the coming years to further our common goals for education, technology and the community.

PaxSpace would also like to welcome The Patuxent Partnership as a partner. I would personally like to thank Bonnie Green, Executive Director for the support and guidance she has provided to PaxSpace. The Patuxent Partnership has agreed to accept charitable donations on behalf of PaxSpace until our non-profit status has been accepted by the IRS. This may take 8-10 months and is greatly appreciated. I would also like to welcome Dr. Ed Barrett from The Patuxent Partnership to PaxSpace’s advisory board of directors.

PaxSpace’s 3D printer “Kossel Clear” from Blue Eagle Labs  has finally shipped and will be arriving Wednesday. We will be assembling, testing and dialing it in over the coming weeks, please stop by and lend your support. See the 3D Printing Forum for status and updates.

If you have an interest in QuadCopters, DC Drones is having a group buy and build at PaxSpace in mid December. The deadline to order for the group buy is tomorrow, November 27th at DC Drone Store. There will be experts from DC Drones to help with the assembly and flying of your QuadCopter. See DC Drones Meetup for more information.

PaxSpace will have a table at the College of Southern Maryland Innovation Showcase on December 7th up in La Plata. We plan on showing some member projects, 3D printing and getting the word out about PaxSpace. If you would like to attend and support this effort, Please contact me at

Some cool projects have been happening at PaxSpace. The ones I know of include: Non-Newtonian Fluid demonstration device; Capacitance touch circuit boards for cub scouts; A raised keyboard shelf; High speed camera integration (2000 frames per second); Instrumented egg drop emulator; Furniture items. RFID entry system part II. Classroom computers setup. If you are working on a project, please post a small description in the Project Forum.

One member has proposed that PaxSpace should hold a mini Maker faire at PaxSpace so that members can display and demonstrate projects they have created over the years. This is a great idea to show the talent we have at PaxSpace and what we are capable of making. With new tools, equipment and space at PaxSpace we will be able to create bigger and better projects. I propose that the first PaxSpace mini Maker Faire be scheduled for next Friday, December 6th. If this sounds good or bad please post your opinion in the comments of this Blog.

The PaxSpace CNC Router project is gathering steam. We have created a dedicated donation fund for the CNC Router and with PaxSpace funds we should start building in December. We have decided to go with a home built solution so that PaxSpace and its members can gain the most knowledge and experience on CNC concepts, design and operation. Our initial concept is a 2’ x 4’ router constructed primarily of wood, plywood and MDF with good electronics and stepper motors that will facilitate upgrading in the future. It is amazing what even a wood framed CNC router is capable of creating. See this site for examples. If you want to participate in the CNC Router project, monitor the CNC Router Forum for status and updates.

Finally, An assortment of training and classes will be available at PaxSpace in December. The computers for the classroom are nearly ready and will be in place soon. If you have an ideas for a class and would like to share your knowledge please contact us using the Suggestions Forum. If anyone has any talent in the holiday decorating department, the timing is perfect.

Sorry for the long winded post. There is a lot going on at PaxSpace and I want to keep everyone informed. Please do not hesitate to comment and post questions to this post. I am looking forward to reading them and will answer any questions promptly.

Thank you for your time,

Jim Shelton

PaxSpace President